5-Day Free Course · Security & Cryptography

Cryptography How Security Actually Works

Cryptography is the foundation of every secure system — HTTPS, authentication, data protection. This course covers the concepts and algorithms every developer and security professional needs to understand.

5 days self-paced
Free forever
Text + external video refs
No signup required
CPU
5
Days
10+
Cryptography Examples
6+
External Videos
$0
Forever Free

No videos. On purpose.

This is a text-first course that links out to the best supporting material on the internet instead of trying to replace it. The goal is to make this the best course on cryptography you can find — even without producing a single minute of custom video.

Intuition before math

You don't need to understand the modular arithmetic behind RSA to understand how public key cryptography works and when to use it. Intuition first.

Applied focus

Every cryptographic concept in this course is connected to how it's used in practice: HTTPS, JWT tokens, password storage, digital signatures.

Links to Computerphile

Computerphile's cryptography videos are the best visual explanations available. This course links to them at the relevant moments.

Completes in 5 one-hour sessions

Each day is designed to finish in about an hour of focused reading plus worked examples. No live classes, no quizzes.

The 5 Days

Each day stands alone. Read them in order for the full picture, or jump straight to the day that answers the question you have today.

The best external videos on this topic.

Instead of shooting our own videos, we link to the best deep-dives already on YouTube. Watch them alongside the course. All external, all free, all from builders who ship this stuff.

Read the source.

The best way to go deeper on any topic is to read canonical open-source implementations. These repositories implement the core patterns covered in this course.

Three kinds of people read this.

Developers Implementing Authentication

You are building authentication systems and want to understand the cryptographic primitives — JWT, password hashing, TLS — you're using.

Security Professionals Building Fundamentals

You work in security and want a solid cryptography foundation beyond "AES is secure" and "use TLS." This course builds that foundation.

Engineers Evaluating Security Designs

You review security designs and need to evaluate cryptographic choices. This course gives you the vocabulary and reasoning to do it.

Want to Master Security Engineering In Person?

The 2-day in-person Precision AI Academy bootcamp covers cybersecurity, cryptography, and AI security — hands-on with Bo. 5 U.S. cities. $1,490. 40 seats max. June–October 2026 (Thu–Fri).

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